Detachable electrical connector



Nov. 21, 1939. J. E BENOIT ET AL 2,130,662

DETAGHABLE ELECTRICAL CONNECTOR Filed Aug. 20, 1938 Patented Nov. 22, E939 UNITED STATES DETACHABLE ELECTRICAL CONNECTOR John Everett Benoit and Clifford B. Reynolds, Willsboro, N. Y.

Application August 20, 1938, Serial No. 225,976 6 Claims. (01. '17a 343) under normal conditions of use and reasonable abuse.

Under many circumstances, notably in the household, in shops, garages, factories and the like, it is particularly desirable to plug an electrical instrumentality, for example a tool, portable lamp or the like, into an electrical outlet. These instrumentalities are connected to the plug by a flexible cord which permits the instrumentality to be moved freely to and from various positions. Accidental pulls on the cord during movement of the instrumentality incidental to its use have a tendency to separate, the customary plug from its socket, which in the case of the best prior art devices of which we are aware results whenever tension on the cord equals the relatively small force which was required to seat the prongs of the plug in the socket. Such accidental and undesired separations of the connector parts are the cause of much annoyance, and a primary object of the present invention is therefore to provide a connector whose separable parts are proof against such undesired separation.

To this end, we provide a combination of plug and socket members which are connected by a sequence of relative movements and which are separated by an inverted sequence of those movements. The inverted sequence of movements is such that it cannot result from pulls on the flexible cord, but requires deliberate manipulation of the plug member.

Ancillary objects of the invention are to provide a. device of this character which is of sim- 40 ple and inexpensive construction, is rugged and durable, and is fool-proof and easily and quickly operable to make and break the electrical conof Fig. 2, and taken on the line 3-3 of Fig. 1, showing the plug member in its initial and final positions;

Fig. 4 is a cross sectional view of the socket member taken on the line 4-4 of Fig. 2;

Fig. 51s a cross sectional view of the socket member taken on the line 55 of Fig. 2;

Fig. 6 is a view showing the socket member in partial longitudinal section, as in Fig. 2, with the plug member connected to it;

Fig. 7 is an end elevational view of the plug member;

Fig. 8 is a side elevational view of the plug member; and

Fig. 9 is a front view of an escutcheon plate for a wall outlet box embodying the invention.

It will be understood that the illustration and description of these preferred forms of the invention are for the purpose of complying with Section 4888 of the Revised Statutes, that they disclose certain embodiments of the invention which have been found in actual practice to give satisfactory and reliable results, and that the appended claims are to beconstrued as broadly as the prior art will permit.

Referring now to the drawing, the reference numeral l designates generally a socket member which is provided with any appropriate means for connecting its enclosed contact elements with the permanent electrical circuit of a building. In the illustrated embodiment the socket member is provided with the familiar threaded base generally designated 2, and which includes a center contact 3 and a rim c ntact 4 separated by insulation 5. The body of the member is made of non-conducting material, such as porcelain or one of the moldable plastics of which the present market affords numerous types now in wide use.

What may be termed the front or forward end wall 6 of the socket member is provided with a rectangular aperture 1, with which communicate a pair of right-angularly related parallel slots 8'. These slots are separated by what may be an integral part of the end wall constituting a sort of block or stop 9 provided for a purp which will be hereinafter explained.

The interior of the socket member behind the block or stop 9 is hollow, providing a chamber which communicates, inside the body of the socket member and behind the block 9, with the aperture 1. In other words, the body of the socketmemberis provided with an approximately L-shaped chamber which opens through the forward end wall of the member and extends therefrom more or less lengthwise into the body and then transversely, all as shown in Fig. 3.

A pair of metallic contactelements, i0, i0, is positioned in the body, one being connected to the rim contact 4, and the other being connected to the center contact). These contact elements extend forwardly into that portion of the hollow of the body which lies at a side of the aperture 1 and immediately behind the slots 8 and block 9. In this hollow the contact elements I II, III assume converging directions, the space between them being of truncated wedge shape with the base of the wedge farther inside the body than the terminal portions of the contact elements. As shown by Fig. 2, these terminal portions are spaced inwardly of the end wall 6. The'portions of the contact elements III; III which lie within the hollow of the body are preferably somewhat resilient and are given a bias toward each other. The plug member of the combination comprises an insulating body H, which may be made of the same kind of material as is used for the body of the socket member. The body Ii is apertured at its rear to receive a conventional conducting cord l2, and is provided at its forward end with a pair of spaced prongs i3, I 3. These prongs are fastened in the body II in any convenient way, and are there connected with the terminals of the two wires of the cord l2. The

prongs l3, l3 are separated by a bridge M of any" suitable strong insulating material and the prongs are preferably relatively divergent in the direction from which they project. from the plug body. The angle of divergence is conveniently made the same as, or a little less than, the angle of convergence of the contact elements Ill, Ill.

The proportions of the prong and bridge assembly. are such that it is easily enterable into the aperture 1 of -the socket member, as shown in dotted lines in Fig. 3. When fully seated in this aperture, the plug member is moved laterally to the full line position of Fig. 3, and the parts are so proportioned that in this movement the bridge M will clear the rear of the block 9, the prongs will enter the slots 8 and will move into engagement with the contact elements ill, l0, thus completing the circuit from the main lines through the cord i2.

To facilitate this lateral entry of the prongs into the slots 8 and engagement thereof with the contact elements l0, l0, these contact elements may be slightly chamfered or twisted in their portions which extend into the hollow of the body of the socket member, so that they define a sort. of trough into which the prong assembly of the plug member is easily received.

When the prong assembly is seated in the aperture 1, its width is slightly less than the width of the space between the contact elements I0, Hi. This facilitates lateral entry of the prong assembly into the space between the contact elements. The plug is then pulled forward a slight distance until it is stopped by engagement of the bridge i l with the rear face of the block 9. This rear face is conveniently beveled reversely from the aperture 1, as shown in Fig. 3, so that the bridge i4 is cammed securely into position behind the block 9. In this slight forward movement of the prong assembly the prongs tend to expand the contact element Iii, Ill, and thus not only force themselves into good electrical engagement with the contact elements, but'by their relative movement tend to keep the surfaces bright and clean.

It will be apparent that accidental pulls on the cord I! will be ineffective to separate the two members of the connection. Separation can be accomplished only by deliberate lateral movement of the plug body, followed by lengthwise withdrawal. The bridge member l4 serves to brace the prongs l3, so that they are permanently maintained against distortion, and will always accurately fit into the openings 1 and 8.

The rear face of the bridge is preferably beveled complementally to the bevel of the block 9. The interflt of these two surfaces is shown in Fig. 3.

In Fig. 9 we show an escutcheon plate I! having a double aperture and slot arrangement like the single arrangement shown in Fig. l in the end wall of the socket body i. It will be understood of course that behind each of these aperture and slot arrangements in the plate I! there is provided a socket or outlet organization substantially like that which has been described. These aperture and slot arrangements may face oppositely, as shown, or in the same direction.

The plate i5 may be provided with outstanding ribs I6 which converge on the aperture and assist in guiding the prong ends squarely into the aperture.

Various modifications and changes in form are contemplated, but all such modifications, to the extent that they embody the principles of the invention as pointed out in the appended claims, are deemed to be within the scope and purview thereof.

We claim:

1. In a detachable electrical connection, a plug member having a body, a pair of conducting prongs extending from the body and separated by a non-conducting bridge spaced from the body, a socket member provided with an end wall having an aperture capable of admitting said prongs and bridge on endwise movement of the same and having a pair of slots extending through the end wall and opening into said aperture and adapted to admit said prongs only on edgewise movement of the same, a portion of said end wall being disposed between said slots and the interior of the socket member behind said end wall portion having a recess, said end wall portion constituting a stop adapted to cooperate with the bridge to prevent endwise withdrawal of the plug member when the bridge is received in said recess, and contact elements positioned in the socket member for engagement with the prongs.

2. In a detachable electrical connection, a plug member having a body, a pair of conducting prongs extending from the body and separated by a non-conducting bridge spaced from the body, a. socket member provided with an end wall -having an aperture capable of admitting said prongs and bridge on endwise movement of the same and having a pair of slots extending through the end wall and opening into said aperture and adapted to admit said prongs only on edgewise movement of the same, a portion of said end wall being disposed between the slots and the interior of the socket member behind said end wall portion having a recess, said end wall portion constituting a stop adapted to cooperate with the bridge to prevent endwise withdrawal of the plug member when the bridge is received in said recess and having its inner face inclined from said aperture toward the outer surface of the end wall to cam the bridge into said recess, and contact elements positioned in the socket member for engagement with the prongs.

3. In a detachable electrical connection, a plug member having a 'body, a pair of conducting prongs extending divergently from the body and separated by a non-conducting bridge spaced from the body, a socket member provided with an end wall having an aperture capable of admitting said prongs and bridge on endwise movement of the same and having a pair 'of slots extending through the end wall and opening into said aperture and adapted to admit said prongs only on edgewise movement of the same, a portion oi! said end wall being disposed between the slots and the interior of the socket member behind said end wall portion having a recess, said end wall portion constituting a stop adapted to cooperate with the bridge to prevent endwise' withdrawal oi the plug member when the bridge is received in said recess, and spring contact elements extending convergently in the socket member having spaced apart portions positionedin said recess for engagement with the prongs.

4. In a detachable electrical connection, a plug member having a body, a pair of conducting prongs extending divergently from the body and separated by a non-conducting bridge spaced from the body, a socket member provided with an end wall having an aperture capable of admitting said prongs and bridge on endwise movement of the same and having a pair ot slots extending through the end wall and opening into said aperture and adapted to admit said prongs only on edgewise movement of the same, a portion of said end wall being disposed between the slots and the interior oi the socket member behind said end wall portion having a recess, said end wall portion constituting a stop adapted to cooperate with the bridge to prevent endwise withdrawal of the plug member when the bridge is received in said recess and having its inner face inclined from said aperture toward the outer surface of the end wall to cam the bridge into said recess, and spring contact elements extending convergently in the socket ing prongs extending from the body and separated by a non-conducting bridge spaced from the body, a socket member provided with an end wall having an aperture capable of admitting said prongs and bridge on endwise movement of the same and having a pair of slots extending through the end wall and opening into said aperture and adapted to admit said prongs only on edgewise movement of the same, a portion of the interior of the socket member being hollow to provide a recess, a stop disposed between said slots and between said recess and end wall adapted to cooperate with the bridge to prevent endwise withdrawal of the plug member when the bridge is received in said recess, and contact elements positioned in the socket member for engagement with the prongs.

6. In a detachable electrical connection, a

plug member having a body, a pair of conduct-- ing prongs extending from the body and separated by a non-conducting bridge spaced from the body and having its face adjacent the body beveled, a socket member provided with an end wall having an aperture capable of admitting said prongs and bridge on endwise movement of the same, and having a pair oi slots extending through said end wall and opening into said aperture and adapted to admit said prongs only on edgewise movement 01 the same, a portion or the interior of the socket member being hollow to provide a recess, a stop disposed between said slots and between said recess and end wall adapted to cooperate with the bridge to prevent endwise withdrawal of the plug member when the bridge is received in said recess and having an sitioned in the socket member for engagement with the prongs when the prongs are entered in 

